Polishing and buffing apparatus



Aug. 6, 1963 R. M. BELL ETAL POLISHING AND BUFFING APPARATUS 2 Sheets-Sheet 1 Filed April 16, 1962 VIIIIm-(V/IIIA INVENTORS H442 JEPSON BY RAMS/IV M BELL ATTOP/VEVS Aug. 6, 1963 R. M. BELL ETAL 3,099,849

POLISHING AND BUFFING APPARATUS Filed April 16, 1962 2 Sheets-Sheet 2 INVENTORS ll/AE JEPSON PAMSAV M. BELL A TTOP/VEVS 3,09,849 PQHSHING AND EUFFENG APPARATUS Ramsay M. Bell, Sehoolcraft, Mich and Ivar Jepson,

Oak Park, Ill., assignors to Hammond Machinery Builders, Inc., Kalamazoo, icln, a corporation of Michigan Filed Apr. 16, 1962, Ser. No. 187,810 11 Claims. (Ql. 15--2l) This invention relates to a polishing and buffing apparatus and particularly to a type thereof adaptable for the polishing and bufiing of nonlinear contours, especially including chamfering the edges of very small holes.

Inasmuch as this invention arose out of a need for chamfering the edges of very small holes, it will be described primarily in connection with such use. However, it should be clearly understood that the following description based on such use is solely for illustrative purposes and is not limiting since the invention is applicable, at least in its broadest sense, to a wide variety of uses involving the polishing or buffing of nonlinearly contoured surfaces.

Referring now to the problem which gave rise to this invention, attention is directed to shaving heads of electric shavers, which shaving heads have a large number of very small openings. The openings may be circular or rectangular, or there may be mixtures and combinations of both rectangular and circular shapes. In all cases, however, such openings are very small. Often the circular openings are of a diameter not exceeding a few thousandths of an inch and the rectangular openings are frequently of a width less than & inch. Since these openings are usually made by a punching operation, as a result of such punching operation there will be created rough edges or burrs around said openings and these must be removed. Further, since a shaving head is rubbed against the face of the user, often with appreciable pressure, it is desirable not only that the burrs around such openings be removed but also that the edges of such openings be chamfered.

The use of butting and/or polishing wheels for the buffing or polishing of workpieces having nonlinearly contoured surfaces has been well known in the past and has been extensively practiced. However, the adaptation of such wheels to nonlinearly contoured surfaces has normally been carried out by arranging a plurality of such wheels along a path to be travelled by the workp'ece and applying said wheels in different directions on and with respect to such workpiece. This is reasonably satisfactory where the contour is such that only a limited number of such directions and, therefore, only a limited number of wheels is required, but where the number of directions involved is large, or infinite as is the case with a circle, then the placement of a plurality of wheels cooperating in a variety of different directions becomes unreasonably complex. Further, where a large number of openings are placed close to each other, it is impossible to apply a plurality of wheels arranged in different directions to each of said openings and, accordingly, the practices of the prior art fail completely to meet the problem above outlined.

Accordingly, the objects of the invention include:

(1) To provide an apparatus for polishing or bufi'ing a nonlinearly contoured surface.

(2) To provide an apparatus, as aforesaid, which is particularly adaptable to polishing or bufiing nonlinearly contoured surfaces, such as the edges of a plurality of very small openings, especially where such openings are either or both circular and rectangular in shape.

(3) To provide an apparatus, as aforesaid, which will 3,699,849 Fatented Aug. 6, 1963 be efiective on openings as small as 2 or 3 thousandths of an inch in diameter and spaced apart similar distances.

(4) To provide apparatus, as aforesaid, which is sufiiciently similar to prior known apparatus that the same can be utilized by ordinary workmen without special training.

(5) To provide apparatus, as aforesaid, which at least in part utilizes equipment already available in existing buffing or polishing machines and hence minimizes the parts which must be manufactured especially for this purpose and which must accordingly be kept stocked by either the manufacturer \OI' user.

(6) To provide apparatus, as aforesaid, which requires only a single builing or polishing wheel for carrying out the complete bufiing or polishing operation on a workpiece having a large number *of such small openings.

(7) To provide apparatus, as aforesaid, which isrelatively simple to construct and which can accordingly be manufactured and maintained in proper operating condi* tion at a cost only a little greater than that of conventional buffer or polisher having a single wheel of a corresponding size and type.

(8) To provide apparatus, as aforesaid, which requires no special adjustments other than those already familiar to persons acquainted with conventional bufiing and pol ishing equipment.

(9) To provide appparatus, as aforesaid, which, while developed primarily for application to the specific problem above set forth, can also be utilizedfor polishing or boiling a wide range of workpieces having nonlinear contours.

Other objects and purposes of the invention will be apparent to persons acquainted with apparatus of this general type upon reading the following disclosure and inspecting the accompanying drawings.

In the drawings:

FIGURE 1 is a top plan view, on a much enlarged scale, of a workpiece of the type which gave rise to the present invention.

FIGURE 2 is a sectional view taken on the line 11-11 of FIGURE 1.

FIGURE 3 is a central, partially schematic, longitudinal sectional view of apparatus embodying theinvention.

FIGURE 4 is a sectional view taken on the line IVIV of FIGURE 3.

FIGURE 5 is an elevational view of a modified arrangement for carrying out the process of the invention.

FIGURE 6 is a schematic view showing another modification.

FIGURE 7 is a view similar to FIGURE 6 showing still another modification.

FIGURE 8 is a schematic indication of one pattern of relative translative movement between the tool and the workpiece.

FIGURE 9 is a schematic indication of another pattern of relative translative movement between the tool and the workpiece.

GENERAL DESCRIPTION In general the invention contemplates rotating a soft metal-working tool, which may be a Wire brush, a textile polishing wheel or other flexible wheel of generally similar kind, rapidly about a cutting axis which is substantially parallel to the general plane of the workpiece, simultaneously rotating the wheel and the shaftabout a spinning axis which is substantially perpendicular to said plane, which extends diametrically across and through said wheel and which extends transverse to and intersects said cutting axis, and, in most cases,simultaneously effects relative translative movement between the tool 3 and the workpiece. Said translative movement may be either continuous or intermittent.

Detailed Construction For illustrative purposes, it will be assumed that the workpiece is of generally planar shape and has a plurality of openings therethrough, as illustrated, that it is arranged for movement intermittently under the wheel and that it moves in a horizontal direction.

Turning now to the apparatus, reference is first made to FIGURE 1 which illustrates a workpiece of the type giving rise to the problem which this invention is intended to solve. There is shown in FIGURE 1 a portion 1 of a standard contact plate for an electric shaver, said plate having a plurality of round openings 2 and rectangular openings 3. FIGURE 2 illustrates a section taken through one of said round openings and showing the rounded contour 4 at the upper end of said opening which it is one purpose of this invention to provide. It should be kept in mind in connection with the following description that said openings 2 are of the order of about i inch in diameter and the rectangular openings 3 are of generally similar size.

In FIGURE 3 the workpiece 1 is shown as supported upon a suitable workholder such as a table 6, of any conventional type. There is provided a post 7 which is rigid with respect to said table 6 and the polishing head is supported thereon. The table 6 and supponting post 7 may be of any conventional type and need no detailed description excepting to note particularly that any kind of work-feeding means may be provided for moving the workpiece 1 with respect to the table 6rtoward and away from the post 7, and that any type of translative means, such as hallways B, supports the table 6 on a frame F for horizontal movement with respect to said frame in a plane parallel to the horizontal plane defined by the axis of rotation of the polishing wheel as said polishing wheel revolves about its spin axis.

The polishing head embodying the invention comprises a bracket 8 which is arranged on the post 7 for vertical movement with respect thereto whereby the vertical position of the polishing head with respect to the table 6 may be adjusted. A substantially cylindrical casing 11 is fixed to the bracket 8 and it has a spacer 12 located therewithin. Combined radial and thrust bearings 13 and 14 are located at the respective ends of the spacer 12. A hollow shaft 16 is rotatably arranged within said bearings 13 and 14 and is held in such position and against axial movement with respect thereto by a nut 17 which is threaded thereon and which bears against the inner race of the upper bearing 14. Said shaft 16 carries a worm wheel 18 at its upper end, which worm wheel is held in place by any suitable means, such as the collar 19. A shaft 21 is rotatably supported on and extends transversely through the upper end of casing 11 and supports a worm 22 which is in mesh with the worm Wheel '18 which may in turn be driven by any suitable means (not shown).

At its lower end, the hollow shaft 16 supports a wheel frame 23, which frame defines an opening 24 for receiving certain hereinafter mentioned gears and also defines a depending shaft housing 26. A counterweight bracket 27 is removably alfixed to the wheel frame 23 by any convenient means, such as bolts or screws, of which one appears at 28.

The lower end of the shaft housing 26 is provided with a bearing 31 which supports one end of a shaft 32. The lower end of the counterweight bracket 27 is provided with a bearing 33 which supports the other end of said shaft 32. The shaft 32 extends substantially parallel with the rtable 6.

spray head 42 at its lower end for the purpose of applying a desired working fluid to the hereinafter-mentioned polishing wheel. A gear 44 is mounted on shaft 38 for rotation therewith and it meshes with a funther gear 46. The gear 46 is mounted on and rotates with a shaft 47 which is located in shaft housing 26 and is rotatably supported therein by hearings 48 and 49. The sharfit 47 carries a bevel gear 51 at its lower .end and said bevel gear is in mesh with a second bevel :gear 52 which is mounted on and rotates with the shaft 32. Shaft 32 carries the polishing wheel 53, which wheel is formed of any flexible material appropriate to the panticular use required. For example, the wheel '53 may be a wire brush, a plurality of bristles of flexible material, or a plurality of disks of paper, cloth or composition material.

In the embodiment shown in FIGURE 3, the extended axis of the hollow shaft 16, hereinafter elsewhere termed the spinning axis, extends diametrically through the axial center of the wheel 53. This will be normally preferred, particularly for purposes of symmetry in construction, and where the apparatus is used for chamfering round holes as above set forth. However, as illustrated in FIGURE 5 and discussed further hereinafter, the spinning axis S may in some cases be offset axially from the center of the wheel 53 providing only that it is still diametric with respect to said wheel 53 and falls at least within that portion of said wheel which contacts the Work.

A pair of plates 54 and 56 are mounted on shaft 32 on either side of the wheel 53 for rotation therewith and for holding the flexible material confined in its polishing position. The plate 56 is held against a collar 57 which in turn abuts against a shoulder 58 on the shaft 32. Hub elements 61 and 62 of any conventional type hold the material comprising the wheel 53, which here may be assumed for illustrative purposes to be a multiplicity of strands or bristles of textile material, and said hub elements are held in position with respect to each other by a nut 63 suitably threaded onto a sleeve 65 extending from the hub element 61. The plate 54 bears against the leftward end of the sleeve 65 and the whole assembly is held together by the nut 64 which is threaded on shaft 32.

Operation One specific manner of operating the apparatus herein described consists of placing a workpiece 1 on the table 6, adjusting the vertical position of the bracket 8 with respect to the post 7 as desired in order to adjust the vertical relationship of the wheel 53 with respect to the workpiece 1 in a known manner and then rotating both the shaft 21 and the shaft 38. Rotation of the shaft 21 will act through the worm 22 and worm wheel 18 to rotate the hollow shaft 16 and thereby rotate the casing 26 and cause the shaft 32 and the wheel 53 to rotate about the above described spinning axis. Thus, the axis of shaft 32 describes a plane parallel to the table. Simultaneously, rotation of the hollow shaft 38 will act through the gears 44 and 46 and thence through the shaft 47 and gears 51 and 52 to the shaft 32 to cause rotation of said shaft 32, and thereby wheel 53, about the longitudinal axis of shaft 32, hereinafter elsewhere referred to as the cutting axis. If desired, suitable cooling, lubricating or cutting fluid may be introduced through the tube 41 and discharged from the head 42 against the wheel 53.

The speed of rotation of the shafts 16 and 32, respectively, may be varied widely according .to the particular type of job involved but in the example above referred to where the objective is to chamfer openings in a shaver head, one typical and satisfactory example of such speeds is 1700 r.p.m. for shaft 32 and turns per minute for shaft 16. However, more generally speaking, the speed of rotation of shaft 32 about the cutting axis will be determined :by the type of polishing, brushing or bufiing required according to know practice. The speed of rotation about the spinning axis will be determined according to the complexity or sharpness of the contours involved. If the contours are relatively sharp or where they are relatively complex, the speed of rotation around the axis of shaft 16 will be relatively low, certain uses having gone as low as ten turns per minute. However, where the contours are relatively wide or simple, such speed may be substantially increased, certain uses of this nature having gone as high as 200 turns per minute.

In this manner the direction of application of the wheel to the work is constantly changed and the changing is effected continuously so that the effect thereof on the work is substantially uniform in all directions.

While different machines by which this invention may be carried out will vary according to the specific character of the workpiece involved and other requirements of a given application, it will be recognized that the following represent at least a few specific examples of such different modes of application.

For example, FIGURE shows an elevational view of a modified device generally similar to FIGURE 3 excepting only that the spinning axis is offset from the axial midpoint of the wheel and is located somewhere between such midpoint and an axial end of the working surface of the wheel. This off-center positioning of the spinning axis will be advantageous for certain nonsymmetrical grinding or where it is desired to cover in a single pass an area of greater diameter than the actual thickness of the wheel being used. However, the holding of the spinning axis within the working surface of the wheel is necessary so that working strokes in an infinite number of working directions can be applied to the workpiece 1 from a center which lies within the work area. Otherwise, the wheel is merely bufiing in a circle and loses the peculiar action obtained by the method and apparatus of the invention.

In the illustration of FIGURE 3, it is assumed that the workpiece may be stationary at a given point in the Working operation with respect to the spinning axis although it may be fed into working position in any convenient manner. Alternatively, as shown in FIGURE 6, the workpiece 1 may be translated with respect to the wheel by moving the workpiece through the zone occupied by the wheel. Further, as shown in FIGURE 7, the wheel may be caused to move across the surface of an otherwise stationary workpiece. Both of these examples of relative translative movement between the wheel and the workpiece may be either single pass movement or reciprocative. Reciprocative relative movement may be repetitive on the same line or simultaneously transversely ofiset in a variety of patterns, such as the two illustrated in FIGURES 8 and 9 by lines T and T The track T is applicable where the irregularitim in contour are arranged in rows; T is applicable where the irregularities in contour are arranged in a random manner. Endless other patterns of relative translative movement are possible.

While certain types of wheels have been above indicated as being appropriate for use in practicing the method of the invention, it will be recognized that any type of wheel which is sufiiciently soft to follow the contour of the work and to apply the type of action required will be acceptable.

A variety of specific structures capable of embodying the invention will be apparent to persons acquainted with apparatus of this general type and, accordingly, it will be recognized that the appended claims can apply to means differing from the specific form of apparatus herein illustrated.

What is claimed is:

1. An apparatus for working a contoured surface on a workpiece comprising, in combination:

a first shaft and means supporting same for rotation about a spinning axis positioned approximately perpendicular to the general plane of said surface;

a second shaft and means supporting said second shaft from said first shaft for rotation about a cutting axis positioned substantially transversely to said spinning axis;

drive means for effecting rotation of said first and second shafts, respectively;

a flexible wheel, said wheel being connected to said second shaft for rotation with said second shaft about the cutting axis and positioned so that said spinning axis extended passes diametrically through said flexible wheel and also through the peripheral portion of said wheel contacting said workpiece, whereby said Wheel may be caused to rotate around said cutting axis and simultaneously to rotate around said spinning axis so that said Wheel applies to the workpiece a Working action in an infinite number of directions through a point therein pierced by said spinning axis.

2. Apparatus according to claim 1 wherein-said wheel is comprised of a multitude of radially extending strands; and including a pair of end plates mounted on said second shaft and located closely adjacent the respective sides of said wheel and extending toward the periphery thereof to limit movement of said strands in a direction axially of said wheel.

3. Apparatus according to claim 1 wherein said wheel is comprised of a multitude of flexible strands.

4. The apparatus defined in claim 1 including a workholder and means supporting said workholder for relative motion with respect to said spinning axis in a direction approximately parallel with said surface.

5. Apparatus according to claim 1 wherein said first shaft is diivingly connected to a wheel frame and said second shaft is rotatably mounted within said wheel frame.

6. Apparatus according to claim 5 wherein a portion of said drive means, provided for rotating said second shaft, is located on one side of the axis of said first shaft; an

counterbalance means on said wheel frame and located on the other side of the axis of said first shaft so that said wlheel frame is balanced about the axis of said first shaft.

7. Apparatus according to claim 5 wherein said drive means includes a third shaft coaxial with and sleeved within said first shaft, and said drive means also includes means within said wheel frame driven by said third shaft and connected for rotating said second shaft.

8. Apparatus according to claim 7 wherein said third shaft is hollow, a tube extending through said third shaft and terminating adjacent said wheel whereby a working fluid can be applied to said wheel.

9. Apparatus for working a contoured surface on a workpiece comprising in combination:

a first shaft, the axis thereof constituting a spinning axis, and means supporting said first shaft for rotation about said spinning axis;

a second shaft, the axis thereof constituting a cutting axis, and means supporting said second shaft for rotation about said cutting axis, said cutting axis being positioned substantially perpendicular to said spinning axis;

means efiecting rotation of said shafts;

a workholder arranged for supporting said workpiece with its said surface substantially parallel with said cutting axis and substantially perpendicular to said SplHIllIlg axis;

a flexible wheel, said wheel being mounted on and for rotation with said second shaft and positioned so that said spinning axis when extended passes diametrically through said wheel and within the peripheral portion of said wheel which contacts said Workpiece and means connecting said means supporting said second shaft and said workholder to said first shaft whereby said wheel may be caused to rotate around said cutting axis and whereby simultaneously relative rotational movement around said spinning axis may be created between said workpiece and said wheel in order that said Wheel applies to the workpiece a working action in an infinite number of directions through a point on said workpiece pierced by said spinning axis.

10. An apparatus for working a contoured surface on a workpiece comprising, in combination:

a frame; a first shaft and means on said frame supporting said first shaft for rotation about a spinning axis;

.a second shaft and means supporting said second shaft 'upon said first shaft for rotation about a cutting axis positioned substantially transversely to said spinning axis;

a flexible wheel connected to said second shaft for rotation with said second shaft about the cutting axis and positioned so that said spinning axis extended passes diametrically through said flexible wheel between the axial ends thereof;

a workholder for supporting said workpiece surface so that said surface is vapproximately perpendicular to said first shaft and is approximately parallel to said second shaft; and

means supporting said Workholder on said frame for movement in a direction parallel to the plane defined by the cutting axis as said cutting taxis revolves about the spinning axis.

11. An apparatus for Working a contoured surface on a'workpiece comprising, in combination:

a first shaft and means supporting same for rotation about a spinning axis positioned approximately perpendicularly to the general plane of said surface;

a wheel frame connected to said first shaft for rotation therewith;

a housing mounted on said wheel frame, extending substantially parallel with said spinning axis and located on one side of said spinning axis;

counterbalance means mounted on said wheel frame, extending substantially parallel with said spinning axis and located on the other side of said spinning axis so that said Wheel frame is substantially balanced about said spinning axis;

a second shaft extending between and rotatably supported on said housing and said counterbalance means, said second shaft being rotatable about a cutting axis positioned substantially transversely to said spinning axis;

drive means for effecting rotation of said first and second shafts, said drive means including a drive element extending through said housing and drivingly connected to said second shaft;

a flexible wheel mounted on said second shaft between said housing and said counterbalance means for roltation with said second shaft about the cutting axis, said flexible wheel being positioned so that said spinning axis extended passes diametrically through said flexible Wheel between the axial ends thereof.

References Cited in the file of this patent UNITED STATES PATENTS 239,170 Hutter Mar. 22, 1881 729,624 Mason June 2, 1903 986,531 Wilson Mar. 14, 1911 1,575,062 Kaiser Mar. 2, 1926 1,583,001 Meints May 4, 1926 2,256,546 Brostrom Sept. 23, 1941 2,915,766 Peterson Dec. 8, 1959 3,044,090 Brauer July 17, 1962 

1. AN APPARATUS FOR WORKING A CONTOURED SURFACE ON A WORKPIECE COMPRISING, IN COMBINATION: A FIRST SHAFT AND MEANS SUPPORTING SAME FOR ROTATION ABOUT A SPINNING AXIS POSITIONED APPROXIMATELY PERPENDICULAR TO THE GENERAL PLANE OF SAID SURFACE; A SECOND SHAFT AND MEANS SUPPORTING SAID SECOND SHAFT FROM SAID FIRST SHAFT FOR ROTATION ABOUT A CUTTING AXIS POSITIONED SUBSTANTIALLY TRANSVERSELY TO SAID SPINNING AXIS; DRIVE MEANS FOR EFFECTING ROTATION OF SAID FIRST AND SECOND SHAFTS, RESPECTIVELY; A FLEXIBLE WHEEL, SAID WHEEL BEING CONNECTED TO SAID SECOND SHAFT FOR ROTATION WITH SAID SECOND SHAFT ABOUT THE CUTTING AXIS AND POSITIONED SO THAT SAID SPINNING AXIS EXTENDED PASSES DIAMETRICALLY THROUGH SAID FLEXIBLE WHEEL AND ALSO THROUGH THE PERIPHERAL PORTION OF SAID WHEEL CONTACTING SAID WORKPIECE, WHEREBY SAID WHEEL MAY BE CAUSED TO ROTATE AROUND SAID CUTTING AXIS AND SIMULTANEOUSLY TO ROTATE AROUND SAID SPINNING AXIS SO THAT SAID WHEEL APPLIES TO THE WORKPIECE A WORKING ACTION IN AN INFINITE NUMBER OF DIRECTIONS THROUGH A POINT THEREIN PIERCED BY SAID SPINNING AXIS. 